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如何构建菜单 Feed

在以下教程中，我们将演示如何使用 Google Protocol Buffers (protobuf) 定义以 JSON 格式构建 Feed。我们将使用 protobuf 编译器根据 protobuf 架构生成源代码。使用生成的源代码构建 Feed 提供了一个简单的界面，并可防止使用不正确的字段名称或字段类型创建 Feed 实体。

项目设置

创建一个新的项目目录。
将 proto 定义中的 food_menu.proto money.proto localized_text.proto 的内容复制为新文件，并复制到项目目录根目录。
安装 protoc 编译器
如需从 .proto 文件生成源代码，您需要 protoc 编译器。从 Protocol Buffers GitHub 版本页面下载最新的预构建二进制文件。

解压缩 ZIP 文件，然后将 bin 路径添加到 PATH 环境变量中，例如：
```
unzip protoc-22.0-linux-x86_64.zip -d /usr/local/protoc
export PATH="$PATH:/usr/local/protoc/bin"
  
```

生成源代码

Python

安装 Python protobuf 库
```
pip install protobuf
    
```
生成客户端源代码。
创建 proto 输出目录：generated
```
protoc --python_out=./generated food_menu.proto money.proto localized_text.proto
    
```
更新 PYTHONPATH 环境变量以包含生成的路径，例如：
```
export PYTHONPATH="$PYTHONPATH:./generated"
    
```
如果您使用的是 Bazel，请尝试使用 py_proto_library 规则作为运行 protoc 的替代方案。

用法示例

如需查看完整示例项目，请点击此处。

"""Menu feed example used in

https://developers.google.com/maps-booking/verticals/dining/guides/tutorials/tutorial-menu-feed-protos#python.
"""
import json
from generated import food_menu_pb2
from google.protobuf.json_format import MessageToDict

# create feed
feed = food_menu_pb2.FoodMenuFeed()

# add a menu component to feed data
menuComponent = feed.data.add()
menuComponent.menu.menu_id = 'menu1'
menuComponent.menu.merchant_ids.append('dining-1')
menuDisplayName = menuComponent.menu.display_name.text.add()
menuDisplayName.text = 'Menu'
menuDisplayName.language_code = 'en-us'
menuComponent.menu.language = 'en-us'
menuComponent.menu.last_merchant_update_time.seconds = 1633621547

for i in ['appetizers', 'dinner']:
  menuComponent.menu.menu_section_ids.append(i)

# add a menu section component to feed data
sectionComponent = feed.data.add()
sectionComponent.section.menu_section_id = 'appetizers'
sectionDisplayName = sectionComponent.section.display_name.text.add()
sectionDisplayName.text = 'Lunch Appetizers'
sectionDisplayName.language_code = 'en-us'
sectionComponent.section.menu_item_ids.append('breadsticks-sauce')

# add a menu item component to feed data
itemComponent = feed.data.add()
itemComponent.item.menu_item_id = 'breadsticks-sauce'
itemDisplayName = itemComponent.item.display_name.text.add()
itemDisplayName.text = 'Breadsticks & Sauce'
itemDisplayName.language_code = 'en-us'
itemDescription = itemComponent.item.description.text.add()
itemDescription.text = 'Breakfast basket w/ side of tomato sauce (size 6 or 12)'
itemDescription.language_code = 'en-us'

for i in ['breadstick-sm', 'breadstick-lg']:
  itemComponent.item.menu_item_option_set.menu_item_option_ids.append(i)

for i in [
    'http://www.example.com/photos/breadsticks.jpg',
    'http://www.example.com/photos/sauce.jpg',
]:
  itemImage = itemComponent.item.images.add()
  itemImage.uri = i

# add a menu item option component to feed data
optionComponent = feed.data.add()
optionComponent.option.menu_item_option_id: 'breadstick-sm'
optionComponent.option.value.property_type = (
    food_menu_pb2.MenuItemOptionProperty.PropertyType.SIZE
)
optionTextValue = optionComponent.option.value.text_val.text.add()
optionTextValue.text = 'Small'
optionTextValue.language_code = 'en-us'
optionOffer = optionComponent.option.offer_set.offers.add()
optionOffer.price.currency_code = 'USD'
optionOffer.price.units = 8
optionOffer.price.nanos = 0

feedJSON = json.dumps(MessageToDict(feed, preserving_proto_field_name=True))
print(feedJSON)

以下代码示例演示了如何创建包含以下各个实体之一的 Feed 对象：

菜单
MenuSection
MenuItem
MenuItemOption

然后，该示例展示了如何将 Feed 序列化为 JSON。

Python API 允许通过设置属性来延迟初始化嵌套对象。

TypeScript

安装 TypeScript protoc 插件。
```
npm init
npm i -D typescript
npm i ts-proto
      
```
请注意，ts-proto 不是受官方支持的 Google 项目。

创建输出目录并生成客户端源代码。

创建 proto 输出目录：src/generated

protoc --plugin="./node_modules/.bin/protoc-gen-ts_proto" --ts_proto_opt=useOptionals=all --ts_proto_opt=snakeToCamel=false --ts_proto_opt=onlyTypes=true --ts_proto_out="./src/generated" food_menu.proto money.proto localized_text.proto

如果您使用的是 Bazel，请尝试使用 js_proto_library 规则作为运行 protoc 的替代方案。

用法示例

如需查看完整示例项目，请点击此处。

import {FoodMenuFeed, Menu, MenuItem, MenuSection, MenuItemOption, MenuItemOptionProperty_PropertyType} from './generated/food_menu';

const menu: Menu = {
  menu_id: 'menu1',
  merchant_ids: ['dining-1'],
  display_name: {text: [{text: 'Menu', language_code: 'en-us'}]},
  language: 'en-us',
  menu_section_ids: ['appetizers', 'dinner'],
  last_merchant_update_time: new Date()
};

const section: MenuSection = {
  menu_section_id: 'appetizers',
  display_name: {text: [{text: 'Lunch Appetizers', language_code: 'en-us'}]},
  menu_section_ids: ['breadsticks-sauce']
};

const item: MenuItem = {
  menu_item_id: 'breadsticks-sauce',
  display_name: {text: [{text: 'Breadsticks & Sauce', language_code: 'en-us'}]},
  description: {
    text: [{
      text: 'Breakfast basket w/ side of tomato sauce (size 6 or 12)',
      language_code: 'en-us'
    }]
  },
  menu_item_option_set:
      {menu_item_option_ids: ['breadstick-sm', 'breadstick-lg']},
  images: [
    {uri: 'http://www.example.com/photos/breadsticks.jpg'},
    {uri: 'http://www.example.com/photos/sauce.jpg'}
  ]
};

const option: MenuItemOption = {
  menu_item_option_id: 'breadstick-sm',
  value: {
    property_type: MenuItemOptionProperty_PropertyType.SIZE,
    text_val: {
      text: [
        {text: "Small", language_code: "en-us"}
      ]
     }
  },
  offer_set: {
    offers: [{
      price: {
        currency_code: "USD",
        units: 8,
        nanos: 0
      }
    }]
  }
};

const feed: FoodMenuFeed = {
  data: [{menu}, {section}, {item}, {option}]
};

console.log(JSON.stringify(feed));

以下代码示例演示了如何创建包含以下各个实体之一的 Feed 对象：

菜单
MenuSection
MenuItem
MenuItemOption

然后，该示例展示了如何将 Feed 序列化为 JSON。

Java

使用 Maven 或 Gradle 将依赖项 protobuf-java 和 protobuf-java-util 添加到您的项目中，如此处所述。
生成客户端源代码。
```
protoc --java_out=src/main/java food_menu.proto money.proto localized_text.proto
    
```
使用 Maven 时，您可以使用 protobuf-maven-plugin 在编译时生成源代码。

如果您使用的是 Bazel，请尝试使用 java_proto_library 规则作为运行 protoc 的替代方案。

用法示例

如需查看完整示例项目，请点击此处。

package com.example;

import com.google.protobuf.InvalidProtocolBufferException;
import com.google.protobuf.Timestamp;
import com.google.type.Money;
import com.google.protobuf.util.JsonFormat;
import com.google.type.LocalizedText;
import food.menu.v1.FoodMenu.FoodMenuFeed;
import food.menu.v1.FoodMenu.Menu;
import food.menu.v1.FoodMenu.MenuComponent;
import food.menu.v1.FoodMenu.MenuItem;
import food.menu.v1.FoodMenu.MenuSection;
import food.menu.v1.FoodMenu.TextField;
import food.menu.v1.FoodMenu.MenuItemOption;
import food.menu.v1.FoodMenu.MenuItemOptionProperty;
import food.menu.v1.FoodMenu.OfferSet;
import food.menu.v1.FoodMenu.Offer;

/**
 * Menu feed example used in
 *
 * <p>https://developers.google.com/maps-booking/verticals/dining/guides/tutorials/tutorial-menu-feed-protos#java.
 */
public class Feed {

  public static void main(String[] args) throws InvalidProtocolBufferException {
    Feed feed = new Feed();
    feed.createMenuFeed();
  }

  public void createMenuFeed() throws InvalidProtocolBufferException {

    Menu.Builder menu =
        Menu.newBuilder()
            .setMenuId("menu1")
            .addMerchantIds("dining-1")
            .setDisplayName(
                TextField.newBuilder()
                    .addText(LocalizedText.newBuilder().setText("Menu").setLanguageCode("en-us")))
            .setLanguage("en-us")
            .setLastMerchantUpdateTime(Timestamp.newBuilder().setSeconds(1633621547));

    MenuSection.Builder section =
        MenuSection.newBuilder()
            .setMenuSectionId("appetizers")
            .setDisplayName(
                TextField.newBuilder()
                    .addText(
                        LocalizedText.newBuilder()
                            .setText("Lunch Appetizers")
                            .setLanguageCode("en-us")))
            .addMenuItemIds("breadsticks-sauce");

    MenuItem.Builder item =
        MenuItem.newBuilder()
            .setMenuItemId("breadsticks-sauce")
            .setDisplayName(
                TextField.newBuilder()
                    .addText(
                        LocalizedText.newBuilder()
                            .setText("Breadsticks & Sauce")
                            .setLanguageCode("en-us")))
            .setDescription(
                TextField.newBuilder()
                    .addText(
                        LocalizedText.newBuilder()
                            .setText("Breadsticks & Sauce")
                            .setLanguageCode("en-us")));

    MenuItemOption.Builder option =
        MenuItemOption.newBuilder()
          .setMenuItemOptionId("breadstick-sm")
          .setValue(
              MenuItemOptionProperty.newBuilder()
                .setPropertyType(MenuItemOptionProperty.PropertyType.SIZE)
                .setTextVal(TextField.newBuilder()
                    .addText(
                        LocalizedText.newBuilder()
                            .setText("Small")
                            .setLanguageCode("en-us"))))
          .setOfferSet(
              OfferSet.newBuilder()
                .addOffers(
                    Offer.newBuilder()
                      .setPrice(
                          Money.newBuilder()
                            .setCurrencyCode("USD")
                            .setUnits(8)
                            .setNanos(0))));

    FoodMenuFeed.Builder foodMenuFeed =
        FoodMenuFeed.newBuilder()
            .addData(MenuComponent.newBuilder().setMenu(menu))
            .addData(MenuComponent.newBuilder().setSection(section))
            .addData(MenuComponent.newBuilder().setItem(item))
            .addData(MenuComponent.newBuilder().setOption(option));

    String feedJSON =
        JsonFormat.printer()
            .omittingInsignificantWhitespace()
            .preservingProtoFieldNames()
            .print(foodMenuFeed);

    System.out.println(feedJSON);
  }
}

以下代码示例演示了如何创建包含以下各个实体之一的 Feed 对象：

菜单
MenuSection
MenuItem
MenuItemOption

然后，该示例展示了如何将 Feed 序列化为 JSON。

Go

安装 Go 的 protoc 插件

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

更新 PATH 环境变量以包含 protoc-gen-go 插件，例如：

export PATH="$PATH:$(go env GOPATH)/bin"

初始化应用并生成客户端源代码。
```
go mod init feed/app
mkdir generated
protoc --go_out=./generated/ food_menu.proto money.proto localized_text.proto
    
```
如果您使用的是 Bazel，请尝试使用 go_proto_library 规则，而不是运行 protoc。

用法示例

如需查看完整示例项目，请点击此处。

/*
Menu feed example used in
https://developers.google.com/maps-booking/verticals/dining/guides/tutorials/tutorial-menu-feed-protos#go.
*
*/
package main

import (
	pb "feed/app/generated/food/menu/v1/proto"
	"fmt"

	localized_text "google.golang.org/genproto/googleapis/type/localized_text"
	money "google.golang.org/genproto/googleapis/type/money"
	"google.golang.org/protobuf/encoding/protojson"
	timestamppb "google.golang.org/protobuf/types/known/timestamppb"
)

func main() {

	//create a menu component
	menu := &pb.Menu{
		MenuId:      "menu1",
		MerchantIds: []string{"dining-1"},
		DisplayName: &pb.TextField{
			Text: []*localized_text.LocalizedText{{
				Text:         "Menu",
				LanguageCode: "en-us",
			}},
		},
		Language: "en-us",
		LastMerchantUpdateTime: &timestamppb.Timestamp{
			Seconds: 1633621547,
		},
	}

	//create a menu section component
	section := &pb.MenuSection{
		MenuSectionId: "appetizers",
		DisplayName: &pb.TextField{
			Text: []*localized_text.LocalizedText{{
				Text:         "Lunch Appetizers",
				LanguageCode: "en-us",
			}},
		},
		MenuItemIds: []string{"breadsticks-sauce"},
	}

	//create a menu item component
	item := &pb.MenuItem{
		MenuItemId: "breadsticks-sauce",
		DisplayName: &pb.TextField{
			Text: []*localized_text.LocalizedText{{
				Text:         "Breadsticks & Sauce",
				LanguageCode: "en-us",
			}},
		},
		Description: &pb.TextField{
			Text: []*localized_text.LocalizedText{{
				Text:         "Breakfast basket w/ side of tomato sauce (size 6 or 12)",
				LanguageCode: "en-us",
			}},
		},
		Pricing: &pb.MenuItem_MenuItemOptionSet_{
			MenuItemOptionSet: &pb.MenuItem_MenuItemOptionSet{
				MenuItemOptionIds: []string{"breadstick-sm", "breadstick-lg"},
			},
		},
	}
	imageUris := []string{
		"http://www.example.com/photos/breadsticks.jpg",
		"http://www.example.com/photos/sauce.jpg",
	}
	for _, uri := range imageUris {
		image := &pb.Image{
			Uri: uri,
		}
		item.Images = append(item.Images, image)
	}

	//create a menu item option
	option := &pb.MenuItemOption{
		MenuItemOptionId: "breadstick-sm",
		Value: &pb.MenuItemOptionProperty{
			PropertyType: pb.MenuItemOptionProperty_SIZE,
			Value: &pb.MenuItemOptionProperty_TextVal{
				TextVal: &pb.TextField{
					Text: []*localized_text.LocalizedText{{
						Text:         "Small",
						LanguageCode: "en-us",
					}},
				},
			},
		},
		OfferSet: &pb.OfferSet{
			Offers: []*pb.Offer{{
				Price: &money.Money{
					CurrencyCode: "USD",
					Units:        8,
					Nanos:        0,
				},
			}},
		},
	}

	//create feed
	feed := &pb.FoodMenuFeed{
		Data: []*pb.MenuComponent{{
			Type: &pb.MenuComponent_Menu{
				Menu: menu,
			},
		},
			{
				Type: &pb.MenuComponent_Section{
					Section: section,
				},
			},
			{
				Type: &pb.MenuComponent_Item{
					Item: item,
				},
			},
			{
				Type: &pb.MenuComponent_Option{
					Option: option,
				},
			}},
	}

	marshalOptions := protojson.MarshalOptions{
		UseProtoNames: true,
	}
	jsonBytes, _ := marshalOptions.Marshal(feed)
	fmt.Printf("message = %s", string(jsonBytes))
}

以下代码示例演示了如何创建包含以下各个实体之一的 Feed 对象：

菜单
MenuSection
MenuItem
MenuItemOption

然后，该示例展示了如何将 Feed 序列化为 JSON。